The current safety and alarm devices for swimming pools and spas on the market today are ineffective and prone to false alarms due to the lack of technology applied in this area. The incidence of childhood drowning is increasing each year as new pool and spa installations continue. The long term objective of this research is to develop a reliable pool and spa alarm system through the adaption of a dual modality detector mechanism that will greatly reduce the number of false alarms without loss of detection sensitivity. The approach will be to develop a detection mechanism utilizing infrared (IR) and ultrasound technology with appropriate electronics to produce an effective, yet cost efficient system, for child safety around swimming pools and spas.